Its resources's usage is not acceptable...below you can see usage without and with opened Firefox...it's terrible and looks like usage of AV or even IS. Sorry but it looks like some big mistake. Moreover it has only free 2-weeks trial...
Without Ff

As the adblocker it works properly...I think...what we can see on examples below: on the top - Adguard is disabled, on the bottom - enabled (of course all other ad/flash/scripts blockers was disabled)

And now "good" news all screensshots was made by using Adguard not as the standalone app but as the browser add-on "Bad" news is that it's only for Chrome.

We’ve got tons of messages asking us to make Adguard free. So we’ve decied to create a free lite version of Adguard for Google Chrome and keep as much functionality as possible. And today we are proud to present you the result of our hard work — Adguard extension.

A few words about some of it features:

Hides advertisements from Web pages and blocks pop-up windows
Protects from visiting phishing or malware websites
Prevents advertising networks and online analytics nodes from tracking your activities online as they tend to do.
How it differs from the full version of Adguard:

The ad gets hidden but is still loaded onto the computer:
There is a risk of being infected with viruses disseminated through the ad networks.
You pay for the traffic used to load the ad.
The ad gets hidden at the last stage of page load which may cause the pages to display at a slower speed.
Approximately 30-35% of the ads cannot be blocked due to the technical restrictions imposed on the extensions.
Limited protection against phishing and malicious pages:
Due to the restrictions imposed on the extension, the page is loaded prior to being checked, therefore, the possibility of phishing and virus attacks is not completely eliminated.
Checking is done only for the page you are going to whereas in the full version of Adguard, all links from which something is loaded get checked.
The extension is compatible only with Google Chrome.
We do not provide technical support for the extension but you can find answers to all of your inquiries on our forum.

Launched 10 times with AppTimer with --incognito and --no-referrers switches (and Adguard plus Avast extensions loaded with flash & PDF plug-in of adobe), average time = 0.3502 without Adguard and Avast it is 0.3430 so this is minimal delay.

It appears the proxy version MITMs HTTPS connections via certificates. You might want to look into the details and think through whether you want to use such an approach.

The web browser, and its extensions, are in the best position to apply same origin based filters (to said web browser's traffic). Especially when Referrer is selectively blocked. You might want to focus some thought and testing on related scenarios if you intend to use the proxy version.

It appears there are malicious site filter options. You might want to look into how those are implemented and whether they involve querying (sending browsing/URL information to) a remote server/database.

Those "free lite version of Adguard for Google Chrome" limitations quoted by ichito sound rather significant. You might want to fully understand those and consider alternatives before using it.

It appears the proxy version MITMs HTTPS connections via certificates. You might want to look into the details and think through whether you want to use such an approach.

The web browser, and its extensions, are in the best position to apply same origin based filters (to said web browser's traffic). Especially when Referrer is selectively blocked. You might want to focus some thought and testing on related scenarios if you intend to use the proxy version.

Click to expand...

Please state the con's your are hinting on

TheWindBringeth said:

It appears there are malicious site filter options. You might want to look into how those are implemented and whether they involve querying (sending browsing/URL information to) a remote server/database.

Click to expand...

Do you know how it is implemented?

TheWindBringeth said:

Those "free lite version of Adguard for Google Chrome" limitations quoted by ichito sound rather significant. You might want to fully understand those and consider alternatives before using it.

Click to expand...

Now I am lost:
1. How do I know whether I fully understand it? Should I also consider alternatives when I partially understand it?
2. Furthermore you leave me clueless about which alternatives to consider, and how many alternatives to consider.
3. Is there a correlation between the level of understanding and number of alternatives to consider, e.g. fully understand = four alternatives, partly understand is two alternatives and little understanding one alternative.
4. When I consider alternatives, what should be the criteria to evaluate these alternatives?

I would like to bring a bit of clarification about Adguard.
Adguard no longer uses lsp driver, instead it uses the TDI and WPF drivers depending on the os. Also not necessarily to run both instances(gui and filtering service). If you close gui, filtration won't stop. And you can turn off https filtration.

Adblocking plugins only hide ads, while Adguard prevents them from loading. Plus it checks all links through our anti-phishing lists, Google Safebrowsing & Web of Trust databases and it blocks websites from tracking you.

I'm actually use it (pro version) on Chrome without any issue, all ads stopped since i use it (2 days), no conflict with side by side security products, speed browsing, even if it's ressource is little bit high this is not a problem for me (ram on board ).

Just one thing in the Browser setting tab, if i delete all others browsers, and keep the chrome one, the icon on the right down side not appears anymore (maybe it's a local bug, someone can confirm that?). when i set"reset to default" all running fine again.